Increasing bacterial resistance to erythromycin is reported. The prolonged use of erythromycin has been questioned in dermatology, because it can lead to bacterial resistance to the pathogen, Staphylococcus aureus (see MRSA), as well as resistance to acne bacteria (C acnes).

How does erythromycin work in skin diseases?

Erythromycin has bacteriostatic effects and prevents the proliferation of bacteria.

It inhibits pro-inflammatorycytokines such as IL-8 and decreases neutrophil oxidative bursts.

How is erythromycin taken?

Oral erythromycin is best taken fasting or just before meals. It comes in a number of bases and formulations.

Base compound

Estolate salt

Ethyl succinate salt

Stearate salt

It is also available as a topical preparation for acne. To reduce antibiotic resistance, a non-antibiotic compound such as benzoyl peroxide or a topical retinoid should be applied when using topical erythromycin.

Side effects of erythromycin

Erythromycin is generally well tolerated. When essential, erythromycin can be used in pregnancy and during breast feeding.

Life threatening arrhythmias (irregularities of the heartbeat ) have been reported in those with an electrical dysfunction that results in a prolonged Q-T interval on electrocardiograph (ECG). This can be due to congenital or acquired heart conditions or electrolyte disturbance (low potassium or magnesium levels)

Drug interactions with erythromycin

Erythromycin has important interactions with other medications. Tell your doctor the names of all medications you are taking, whether prescribed or purchased without prescription.

Erythromycin should not be taken with terfenadine, astemisole or cisapride because it could result in dangerous irregularities of the heartbeat and sudden death. These drugs are no longer available in New Zealand.

Other drugs that can prolong the Q-T interval include amiodarone, risperidone, haloperidol, citalopram and ciprofloxacin.

Erythromycin can increase the concentration of the following medications resulting in potentially toxic levels.

Warfarin (additional prothrombin time blood tests are necessary)

Statins, particularly simvastatin and atorvastatin. Toxicity results in muscle pain and weakness, which may be serious. If long-term treatment with a statin and erythromycin is required, suitable alternatives are fluvastatin, pravastatin and rosuvastatin.

New Zealand approved datasheets are the official source of information for these prescription medicines, including approved uses and risk information. Check the individual New Zealand datasheet on the Medsafe website.